Thread-controlling device for sewing-machines



[ i (No Model.)-

R. G. WOODWARD. Y THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

No. 427,026. Patented Apr. 29, 1890.

M365. fwwwofi M g; ,j Maw anwooahu i ywzm I 3M UNITED STATES PATENT Criics,

RUSSEL G. IVCODIVARD, OF IVAUKEGAN, ASSIGNOR TO THE UNION SPECIALSEW'ING MACHINE COMPANY, OF CHICAGO, ILLINOIS.

THREAD-CONTROLLING DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 427,026, dated April29, 1890.

Application filed March 30, 1889. Serial No. 305,362. (No model.)

To aZZ whom, it may concern.-

Be it known that 1, Russian G. W OODWARD, of \Vaukegan, county of Lake,State of Illinois, have invented an Improvement in Take- Up forSewing-Machines, of which the followin g description, in connection withthe accompanying drawings, is a specification, like letters on thedrawings representing like parts.

This invention has for its object to provide a sewing-machine with athread-controller which shall have its position varied automaticallytoprovide for variations in thickness of the cloth or other material underthe presserfoot, and thus give to the needle and stitchforming devicessufficient slack thread to accord with the thickness of the material.

In this invention the presser-bar has an attached rack which rises andfalls in unison with it, the teeth of the said rack engaging with teethat the end of a thread-controlling lever, having a long arm which isextended from its fulcrum backwardly toward the tension device, where itis provided withan eye to receive the thread.

To make the thread-controlling lever light, so that but little power isrequired to move it, the said lever has been constructed of a plate anda wire.

My invention consists, essentially, in the combination, with thework-support, presserfoot, presser-bar, and rack attached thereto andrising and falling with the presser-ba1',ot a thread-controlling leverhaving teeth at one end and an eye at the other end, and it beingadapted to act upon the thread on its way to the eye of the needle andcause more slack thread to be given to the needle as the thickness ofthe material under the presser-foot varies, and vice versa.

Figure l in side elevation represents a suificient portion of asewing-machine to enable my invention to be understood, the needle-barbeing partially broken out to show the presserbar and rack attachedthereto behind it, the thread-controlling lever being shown by clottedlines in the position it would occupy if the thickness of the materialshould be increased, as shown by dotted lines under the presser-foot;and Fig. 2 is a detail to be referred to.

The bed-plate A, the overhanging arm A,

containing the usual bearings for the needle and presser bars, theneedle-actuating arm B, the link B, connected to a block secured to theneedle-bar B are partially broken out in Fig. 1. The said needle-bar andthe presserbar C and presser-foot C are and may be all of usualconstruction. The presser-bar C has applied to it the collarC ,formingpart of the rack C, having teeth 2, the said hub having a projection c,the collar being held in adjusted position on the presser-bar by asetscrew 0. The pin or projection c is in practice acted upon by asuitable strong spring 0 attached at its opposite end to the overhangingarm A, the said spring normally acting to keep the presser-foot downupon the material under it. The spring 0 is of common use insewing-machines.

The overhanging arm A has a stud-screw D, which constitutes the fulcrumfor the thread-controlling lever D,havin g at one end a series of teeth3, to be engaged by the teeth 2 of the rack C, which, as described, isconnected to and rises and falls in unison with the presser-bar,according to the thickness of the material under the presser-foot.

The lever D, to make it light and yet sufficientlysti'ff, has a part ofit composed of wire, as at 4, the said wire being bent at its outer endto form a socket for the reception of a stud-screw 5, to secure to theend of the threadcontroller the eye (3, through which the needlethread15 is passed after leaving the usual tension device it, the saidneedle-thread being represented as carried through an ordinary loop oreye Z) at the upper end of the needlebar, and thence through the eye ofthe usual eye-pointed needle.

The tension device may and in practice will 0 be substantially the sameas in United States Patent No. 3%,493, dated June 29, 1886.

In operation, as the material varies in thickness-say, for instance, asthe material increases in thickness-the presser-foot rises 5 and causesthe eye 6 to descend, as represented by dotted lines, and effect theproduction of more slack in the needlethread, so that when the needledescends more slack will be given up to the formation of the stitch thanI00 when the material under the presser-foot is thinner. By extendingthe lever D well back 5 as described.

toward the tension device a slight movement of the resser-bar givesconsiderable movement to the lever between the tension device and itspoint of support on the needlebar.

I claim- 1. The COIllbli ;LLlOil,\\lilll the work-sn1r)port, needle bar,presser foot, presser bar, rackplate connected to and rising and fallingwith the resser-bar, and a tension device, of the pivotedthreadcontrolling lever having teeth engaged by the said rack andextended horizontallytoward the tension device and acting on theneedle-thread between the tension device and needle-bar, to operatesubstantially 2. The n'esser-har, its attached toothed

